Doctors in the southern Nigerian state of Edo have gone on strike to protest at the kidnapping of a colleague.

The director of a hospital in Benin City was abducted by unknown gunmen while he was on his way home from work.

Dr Osahun Enabulele, a spokesman for the Nigerian Medical Association, told the BBC the doctors were angered by the lack of security in Edo state.

In August 2009, doctors staged a demonstration in Edo after five co-workers were kidnapped.

The current strike started on Wednesday and involves more than 50 doctors at the University of Benin Teaching Hospital.

Dr Enabulele said the Association's members were only treating emergency cases.

Edo's Commissioner for Health Dr Moses Momoh told the BBC's Abdul Mohammed Isa the authorities were doing everything possible to find the kidnapped man.

He called on the striking doctors to return to work in the interests of their patients' health.

But the doctors have said they will strike until their colleague is found and released.